Luton men Ibrahim Anderson and Shah Jahan Khan have been charged by police for allegedly recruiting people to join a proscribed group.
Anderson, 38, of Dallow Road, Luton and Khan, 62, of St Catherine's Avenue, also in Luton, were arrested in December and were charged with terrorism offences on Thursday (26 March) following an investigation by the Metropolitan Police's Counter Terrorism Command.
Both men were charged with inviting support for a proscribed organisation contrary to section 12 of the Terrorism Act 2000 in August last year.
Anderson is also accused of possessing information of a kind likely to be useful to a person committing or preparing an act of terrorism contrary to section 58 of the Terrorism Act 2000.
There are 63 international terrorist organisations proscribed under the Terrorism Act 2000 and 14 organisations in Northern Ireland that were proscribed under previous legislation.
Outlawed groups include Al Muhajiroun, al-Qaeda and the Islamic State of Iraq and the Levant (Isis).
They have both been bailed to appear at Westminster Magistrates' Court on Tuesday, 21 April.